Impact & improvement of tool deviation in friction stir welding: Weld quality & real-time compensation on an industrial robot

The present study proposes the use of an industrial serial robot to reduce the investment cost and to increase the process flexibility of Friction Stir Welding (FSW). The first part of the study characterizes the impact of pin axis position on FS Weld (FSWed) quality. The second part shows a method to compensate the lateral pin deviation in real-time during Robotic Friction Stir Welding (RFSW). This paper shows that a robot with an embedded real-time algorithm for the compensation of the lateral tool deviation can reproduce the same FSWed quality as a gantry-type CNC system. The elastostatic model of an industrial robot is carried out by the classical identification technique and this is embedded in the robot controller. Based on force measurements along the welding process, the corrected path is calculated in real-time. (C) 2015 Elsevier Ltd. All rights reserved.